Many years and millions of dollars for our Artificial Heart Program, lead to survival of six months in calves. We now will deliver a preclinical package for human application (manufacturing, materials, criteria for selection of patients, technique of implantation, postoperative care, management and function). Tethered to a silent, moveable drive system, the recipient will be able to walk and play golf. Long term animal experiments will predict complications, their frequency, their avoidance and therapy and the expected life time. No funds for clinical work are requested. (1) We will learn to implant artificial hearts virtually without mortality and prove functional integrity of both animal and artificial heart. We will study physiological, pathological and basic problems using air driven hearts since they are versatile and available. (2) Electrically driven hearts will be studied to gradually replace air driven hearts. Specific problems are e.g. alternate pumping mode and the difference in cardiac output between the left and right side. (3) Our blood materials-interaction studies have greatly reduced the blood damage and thrombosis but will be continued and refined. Controlled release of anticoagulants will be added. Studies of soft tissue materials interaction will continue for devices and percutaneous leads. (4) Implantation of artificial hearts followed by transplantation in chimeric twin calves is a preclinical study to help patients now dying (while waiting for a transplant, 8 per year). It also offers opportunity for comparative study. (e.g., of the role of the atrium). (5) The Artificial Heart can produce controlled heart failure and reverse it, right or left or both sides; a unique investigative tool and preclinical tool to determine the reversibility of the consequences of heart failure. Project (6) Offers more physiological, practical, basic, and pharmacological studies since the artificial heart allows separation of central and peripheral effects. Our St. Mark's core is a resource of value for the Artificial Heart Program of the NIH.